To the Editor.— With the United States advancing toward a "smokeless society," smokers, perhaps fearing stigma, perhaps feeling shame, perhaps simply being deceptive, may increasingly choose not to reveal their smoking to their physicians. We cite a recent example of such a phenomenon.We examined 52 adults with allergic asthma who were enrolled in a study during which tobacco use was incidentally ascertained. During this protocol, seven (14%, with a 95% confidence interval [CI] of 6% to 26%) of the 52 patients revealed, in confidence, that they smoked, a finding that had gone undetected during their clinical evaluations. Their smoking was therefore not known to the physicians who treated their asthma. Moreover, as vital as this information was, it had not been forthcoming, despite the fact that multiple measures should have elicited it, including new patient evaluation performed by the allergy-immunology service, with specific attention to "exacerbating factors"; documentation